1. Field of the Invention
The invention relates to a light guide plate and an edge-lighting type backlight module.
2. Description of the Related Art
FIG. 1A shows a schematic diagram illustrating a conventional edge-lighting type backlight module 10. Referring to FIG. 1A, the edge-lighting type backlight module 10 includes a back plate 11, a light guide plate 12, a reflective sheet 13, and a light source (not shown). The light guide plate 12, reflective sheet 13 and light source are disposed on the back plate 11, the reflective sheet 13 is adjacent to a bottom surface 122 of the light guide plate 12, and the light source is disposed near a side surface of the light guide plate 12. The light guide plate 12 is a transparent plate. Light beams emitting from the light source are repeatedly totally reflected by a top surface 121 and the bottom surface 122. The bottom surface 122 is provided with multiple V-shaped grooves 123 for guiding most of light beams toward the top surface 121 to obtain high luminance.
Though the backlight module 10 has high luminance, the backlight module 10 also has inferior luminous uniformity since the brightness of partial regions of the light guide plate near the light source is larger than the brightness of partial regions of the light guide plate far from the light source. FIG. 1B shows a schematic diagram illustrating another conventional edge-lighting type backlight module 10′. As shown in FIG. 1B, in the edge-lighting type backlight module 10′, the interval between two adjacent V-shaped grooves 123 near a light source (not shown) is set as larger than the interval between two adjacent V-shaped grooves 123 far from the light source to achieve better luminous uniformity. However, such design gives limited improvement on the luminous uniformity and adds considerable complexity to the design and fabrication of a backlight module.